Influence of metakaolin additive and nanoparticle surface treatment on the durability of white cement based concrete

Abstract

This article is focused on the durability of white cement-based concrete treated with a nanoparticle coating developed for the production of facade panels. The mixtures under study were modified by the addition of metakaolin, which was applied as a cement replacement up to 22.5%. Metakaolin was used to increase primary resistance of the concrete to impacts from the environment. Final properties were investigated by means of compressive strength, chloride migration test, initial surface absorption test, and frost resistance. The efficiency of the surface treatment was evaluated in terms of transport properties and changes after the temperature cycling. The performed experimental program confirmed a positive influence of metakaolin addition in terms of all studied parameters; however, 15% replacement can be assumed as an optimum. The nanoparticle treatment contributed significantly to the mitigation of transport properties of the concrete mixtures. Nevertheless, cyclic temperature loading slightly reduced its tightness; local water and also chloride ions ingress was recorded. The experiments confirmed the strong potential for additional surface treatment based on the nanotechnology, but also accented the necessity of including tasks of long-term durability and primary resistance of concrete to the entire design of the structural elements.